A marginal cost method for quantitative assessment of the load- and non-load-related shares of pavement rehabilitation expenditures is described. A set of ordinary least-squares models was formulated by an aggregate approach. The study revealed that the shares of pavement rehabilitation expenditures attributable to load factors depend on pavement type, year of study, and other variables. The load- and non-load-related fractions of rehabilitation expenditures used to repair pavement damage were found to be 28% and 72%, respectively, for flexible pavements, 78% and 22%, respectively, for jointed concrete pavements, and 38% and 62%, respectively, for composite pavements. It is expected that the results of the study will facilitate the apportionment of pavement rehabilitation expenditures for highway cost allocation in a fair and equitable manner.